A fast-growing short-lived tree as is the native Black Cottonwood, a specimen which may sometimes burst apart suddenly during summer. A friend has been doing ecological work up in a large Black Cottonwood on the Olympic Peninsula and heard another big example in the same drainage explode into fragments. If the team had instead been climbing in the other tree, that would have been it for them.

However, the structural failure of Sweetgum that makes an impression in Seattle is when the tops of numbers of them break out under wet snow. This may be much more of a problem with more southerly origin forms that hang onto their still mostly green leaves well into December than with those that defoliate earlier in fall.